Ross's Gull

Ross's Gull (Rhodostethia rosea) is a delicate Arctic gull with a wedge-shaped tail, pale grey wings and a narrow black neck collar in breeding plumage. Body shape, bill structure, plumage pattern and voice provide the strongest field characters. Age, sex and season may alter its appearance, so identification should combine several features and careful direct comparisons with similar species in the same habitat (Wikipedia, general species account).

It breeds in northeastern Siberian wetlands and feeds on small fish and invertebrates over Arctic seas during dispersal. Its movements and social behaviour vary through the year, with breeding birds generally more dispersed and non-breeding birds gathering where food is concentrated. Japanese records place it within the country's documented avifauna as a resident, migrant or visitor (Wikipedia, general species account; Wildlife of Japan occurrence records).